Empirical Formula: C₁₀H₁₃NO₂
Molecular Weight: 179.2157 g/mol
EINECS: 209-713-3 
Index of Refraction: 1.548
Density: 1.099 g/cm³
Flash Point: 164.8 °C
Enthalpy of Vaporization: 59.33 kJ/mol
Boiling Point: 348.8 °C at 760 mmHg
Vapour Pressure: 4.89E-05 mmHg at 25 °C
Structure of m-Acetophenetidide (CAS NO.591-33-3):
                      
IUPAC Name: N-(3-Ethoxyphenyl)acetamide
Canonical SMILES: CCOC1=CC=CC(=C1)NC(=O)C
InChI: InChI=1S/C10H13NO2/c1-3-13-10-6-4-5-9(7-10)11-8(2)12/h4-7H,3H2,1-2H3,(H,11,12)
InChIKey: YVTBOWVWYXJHLD-UHFFFAOYSA-N

Reported in EPA TSCA Inventory.

Moderately toxic by ingestion. See also p-ACETOPHENETIDIDE. When heated to decomposition it emits toxic fumes of NO_x.
Hazard Codes of m-Acetophenetidide (CAS NO.591-33-3): Xn
Risk Statements: 22 
R22:Harmful if swallowed.
Safety Statements: 22 
S22:Do not breathe dust.

 m-Acetophenetidide , its cas register number is 591-33-3. It also can be called 3'-Ethoxyacetanilide ; N-(3-Ethoxyphenyl)acetamide ; and Acetamide, N-(3-ethoxyphenyl)- . It is hazardous, so the first aid measures and others should be known. Such as: When on the skin: should flush skin with plenty of water immediately for at least 15 minutes while removing contaminated clothing. Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. While, it's inhaled: Remove from exposure and move to fresh air immediately. Then you have the ingesting of the product: If victim is conscious and alert, give 2-4 cupfuls of milk or water.
In addition, m-Acetophenetidide (CAS NO.591-33-3) could be stable under normal temperatures and pressures. You must not take it with strong oxidants. And also prevent it to broken down into hazardous decomposition products: nitrogen oxides, carbon monoxide, irritating and toxic fumes and gases, carbon dioxide, nitrogen.